1,355,303 research outputs found
I miei archivi videoteatrali : Anna Maria Monteverdi intervista Fernando Mastropasqua
No full textIntervista al prof. Mastropasqua in relazione al suo Archivio audiovisivo privato, una fonte inesauribile per ogni ricerca e studio: catalogati in ordine alfabetico (da Antonello Aglioti a Friederich Zelnik), i materiali del suo ricchissimo archivio incrociano teatro, cinema, operetta, varietà, danza attraverso regi-strazioni video e audio, tra vinili audiocassette e dvd, testimoniando le ricerche trasversali di Mastropasqua, tra antropologia, teatro dell’avanguardia e teatro classico; la ricerca tea-trale è testimoniata dal Living, da Carmelo Bene, Luca Ronconi, Peter Brook senza trascu-rare la vasta raccolta di video testimonianze, documentari e interviste. I film ispirati al tea-tro sono quelli di Ernst Lubitsch, di Peter Greenaway fino a Tom Stoppard, Trevor Nunn, Lars von Trier e Kenneth Branag
Correction: Corrigendum: Optical coherence tomography angiography microvascular findings in macular edema due to central and branch retinal vein occlusions
No full textScientific Reports 7: Article number: 40763; published online: 18 January 2017; updated: 23 February 2017 The original version of this Article contained errors in the spelling of authors Rodolfo Mastropasqua, Lisa Toto, Luca Di Antonio, Enrico Borrelli, Alfonso Senatore, Marta Di Nicola, Giuseppe DiMartino and Marco Ciancaglini, which were incorrectly given as Mastropasqua Rodolfo, Toto Lisa, Di Antonio Luca, Borrelli Enrico, Senatore Alfonso, Di Nicola Marta, Di Martino Giuseppe, Ciancaglini Marco respectively.</jats:p
S100 A and B expression in normal and inflamed human limbus
No full textPURPOSE: To study the expression of S100 A and B family proteins in normal human limbus and to analyze modification of the expression in inflammatory conditions.
METHODS:
The total expression of members of the S100 family and the expression of A4, A8, A9, and B individually were evaluated in nine normal human corneal limbi, collected from cadaver healthy donors, in particular in the limbal epithelial crypts (LECs), and in five inflamed limbi obtained from enucleated eyes. S100 protein distribution was determined with immunohistochemistry staining analysis.
RESULTS:
Cytoplasmic expression of total S100 proteins was observed in 100% of LECs; in contrast, the inflamed tissues were completely negative, and faint positivity was observed in only one case. Moreover, cytoplasmic expression of S100 A4 and A9 was uniformly found in the entire LECs in all samples analyzed, while S100 A8 positivity was observed in only 44.4% of cases and only in the cells localized in the central area of the LEC. Positivity for S100 B was not observed in all samples analyzed.
CONCLUSIONS:
As reported in the literature, normal limbal epithelial cells show strong expression of S100 proteins. A novel finding of this study was the expression for the limbal epithelial crypts. In particular, S100 A4 and A9, which are normally involved in regulating a wide range of biologic effects, including cell motility, survival, and differentiation, are the most expressed members in healthy limbal crypts. In inflamed tissues, expression of S100 proteins was dramatically decreased. S100 proteins, and in particular S100 A4 and S100 A9, can be useful as markers of early changes in stem cell niches due to inflammatio
The interplay of roughness and adhesion in viscoelastic sliding contacts
No full textGarantire un controllo efficace dell'adesione nei materiali viscoelastici rappresenta una sfida cruciale nella tribologia moderna, con implicazioni significative in un ampio spettro di applicazioni ingegneristiche, tra cui mescole per battistrada di pneumatici per una maggiore aderenza ed efficienza, pinze robotiche morbide con adesione reversibile, adesivi strutturali e sensibili alla pressione, sistemi adesivi bio-ispirati e dispositivi MEMS. Nonostante i risultati sperimentali abbiano evidenziato come l'interazione tra l'adesione dell'interfaccia e la viscoelasticità influenzi il comportamento di contatto delle interfacce reali, gli attuali approcci analitici e numerici possono descrivere con precisione solo condizioni senza adesione in presenza di movimento relativo tra solidi o richiedono potenziali interatomici locali ad hoc per imitare gli effetti adesivi. Le osservazioni di fenomeni quali perdite isteretiche, isteresi di adesione e forza adesiva dipendente dalla velocità sottolineano ulteriormente i limiti di questi modelli esistenti, che spesso si basano sulla separazione di scala o ipotizzano un comportamento puramente elastico. Basandosi su un'estensione precedentemente sviluppata del criterio di frattura di Griffith ai materiali isteretici, questa tesi estende ulteriormente il quadro al caso multi-contatto irregolare e lo utilizza per studiare il comportamento di contatto e attrito di diversi profili irregolari multiscala in presenza di adesione interfacciale, attraverso l'intero spettro viscoelastico del materiale. Sfruttando la metodologia degli elementi di contorno basata sull'uso della funzione di Green, le equazioni di chiusura energetica sono state ottenute imponendo, su ciascun bordo di contatto, un equilibrio tra il lavoro delle sollecitazioni interne e quello dell'adesione in presenza di variazioni infinitesimali virtuali del dominio di contatto. Partendo dall'ipotesi di forze adesive a raggio infinitamente corto, l'approccio proposto estende i concetti classici di frattura per tenere conto della dissipazione di energia non conservativa derivante dalle sollecitazioni viscoelastiche. La struttura matematica e fisica di questa formulazione energetica si discosta significativamente dai casi elastici equivalenti, consentendo un trattamento coerente degli effetti di isteresi sia di massa che interfacciali. I risultati mostrano un marcato aumento dell'area di contatto, della forza adesiva e dell'attrito, in particolare a velocità di scorrimento intermedie, determinato dalla coesistenza dell'isteresi di adesione indotta dalla viscoelasticità su piccola scala ai bordi dei contatti e dell'isteresi di massa generata dalla viscoelasticità su larga scala, a conferma dei risultati di precedenti studi simili su un penetratore sinusoidale. Affrontando l'interazione fondamentale tra viscoelasticità, rugosità e adesione, questo lavoro stabilisce una base teorica unificata che spiega le principali osservazioni sperimentali e supporta la progettazione razionale di materiali viscoelastici con proprietà adesive e tribologiche su misura.Ensuring effective control of adhesion in viscoelastic materials represent a crucial challenge in modern tribology, with significant implications across a broad spectrum of engineering applications, including tire tread compounds for enhanced grip and efficiency, soft robotic grippers with reversible adhesion, structural and pressure-sensitive adhesives, bio-inspired adhesive systems and MEMS devices. Despite experimental results have highlighted how the interaction between interface adhesion and viscoelasticity affects the contact behavior of real interfaces, current analytical and numerical approaches can accurately describe only adhesiveless conditions in presence of relative motion between solids or require ad hoc local interatomic potentials to mimic adhesive effects. Observations of phenomena such as hysteretic losses, adhesion hysteresis and velocity-dependent adhesive strength further underline the limitations of these existing models, which often rely on scale separation or assume purely elastic behavior. Building upon a previously developed extension of Griffith’s fracture criterion to hysteretic materials, this thesis further extends the framework to the rough multi-contact case and employs it to investigate the contact and friction behaviour of several multiscale rough profiles in the presence of interface adhesion, across the entire viscoelastic spectrum of the material. Exploiting the boundary element methodology based on the use of the Green's function, the energy closure equations were obtained by imposing, at each contact edge, a balance between the work of internal stresses and that of adhesion under virtual infinitesimal variations of the contact domain. Moving from the assumption of infinitely short-range adhesive forces, the proposed approach extends classical fracture concepts to account for non-conservative energy dissipation arising from viscoelastic stresses. The mathematical and physical structure of this energy formulation significantly departs from equivalent elastic cases, allowing for a consistent treatment of both bulk and interfacial hysteresis effects. The results shows a marked increase in contact area, adhesive strength and friction, particularly at intermediate sliding velocities, driven by the coexistence of adhesion hysteresis induced by small-scale viscoelasticity at the edge of the contacts and bulk hysteresis generated by large-scale viscoelasticity, supporting the findings of previous similar studies for a sinusoidal indenter. By addressing the fundamental interplay between viscoelasticity, roughness and adhesion, this work establishes a unified theoretical foundation that explains key experimental observations and supports the rational design of viscoelastic materials with tailored adhesive and tribological properties
COLLASSO DI SISTEMI SPAZIALI A VOLTA RIBASSATA IN ACCIAIO PER EVENTI ESPLOSIVI
No full textVengono introdotti, affrontati e analizzati i fenomeni di collasso strutturale dinamico di sistemi spaziali a volta ribassata (skylights, calotte, cupole) realizzati per accoppiamento di acciaio strutturale e vetro di rivestimento. In particolare, lo studio viene condotto con riferimento ad un sistema acciaio-vetro di prossima realizzazione a pianta ellittica ed assi 60m e 54m, con fattore di ribassamento critico.
Le analisi hanno visto l’adozione di opportuni modelli matematici di generazione del segnale di “onda di pressione” come funzione del tempo, e la differenziazione dei valori di intensità di pressione relativamente alla forma della copertura ed alla posizione dell’evento esplosivo.
La risposta strutturale è stata dunque indagata per mezzo di analisi temporali al passo, parametrizzandosi le intensità del segnale di onda d’urto, il ribassamento geometrico della copertura e le proprietà inerziali delle sezioni strutturali.
Modelli elasto-plastici del materiale acciaio in comportamento accoppiato assial-flessionale sono stati adottati in accordo ad EN1993:2005
Theoretical analysis of mixed open-circuit potential for high temperature electrochemical cells electrodes
No full textThe Nernst equilibrium potential calculates the theoretical OCV, which estimates the best performance achievable by an electrochemical cell. When multiple semi-reactions (or multiple ionic species) are active in one of the electrodes, the calculation of the theoretical OCV is not straightforward, since different Nernst potentials are associated to each semi-reaction. In this paper, analytical equations for calculation of the theoretical OCV are developed, using the mixed potential theory. The case of H2 and CO co-oxidation (or H2O and CO2 co-reduction) in solid oxide cells is used as a reference case, but similar conclusions can be drawn for other equivalent cases. OCV data from literature are used to calibrate and validate the model. The relative reaction rate of H2 and CO semi-reactions is estimated within the calibration process, and the result is in line with assumptions and suggestions given by other authors. The validation procedure shows predicted OCV values in line with experimental literature data, except for mixtures with relatively large CH4 concentration (e.g., 8%), for which the OCV is significantly underestimated. This is expected when thermochemical reactions, in parallel to electrochemical reactions occur, since the additional H2 produced by internal steam methane reforming is not accounted within the local mixed potential model. A fuel cell polarization model is developed based on the results from the calibration procedure, and it is used to predict the polarization behavior of an SOFC fed with a H2-H2O-CO-CO2 fuel mixture. It is found that either H2 or CO may be reduced rather than oxidized via an equivalent electrochemical water-gas-shift reaction
High-Intensity Focused Ultrasound Circular Cyclocoagulation in Glaucoma: A Step Forward for Cyclodestruction?
No full textThe ciliary body ablation is still considered as a last resort treatment to reduce the intraocular pressure (IOP) in uncontrolled glaucoma. Several ablation techniques have been proposed over the years, all presenting a high rate of complications, nonselectivity for the target organ, and unpredictable dose-effect relationship. These drawbacks limited the application of cyclodestructive procedures almost exclusively to refractory glaucoma. High-intensity focused ultrasound (HIFU), proposed in the early 1980s and later abandoned because of the complexity and side effects of the procedure, was recently reconsidered in a new approach to destroy the ciliary body. Ultrasound circular cyclocoagulation (UC3), by using miniaturized transducers embedded in a dedicated circular-shaped device, permits to selectively treat the ciliary body in a one-step, computer-assisted, and non-operator-dependent procedure. UC3 shows a high level of safety along with a predictable and sustained IOP reduction in patients with refractory glaucoma. Because of this, the indication of UC3 was recently extended also to naïve-to-surgery patients, thus reconsidering the role and timing of ciliary body ablation in the surgical management of glaucoma. This article provides a review of the most used cycloablative techniques with particular attention to UC3, summarizing the current knowledge about this procedure and future possible developments
In vivo confocal microscopy of conjunctiva-associated lymphoid tissue in healthy humans
No full textPURPOSE: To investigate modifications with aging of the presence, distribution and morphologic features of conjunctiva-associated lymphoid tissue (CALT) in healthy human subjects using laser scanning in vivo confocal microscopy (IVCM).
METHODS:
A total of 108 (age range, 17-75 years) subjects were enrolled. In vivo confocal microscopy of the tarsal and bulbar conjunctiva, and impression cytology (IC) with CD3 (intra-epithelial T-lymphocytes) and CD20 (intra-epithelial B-lymphocytes) antibody immunofluorescence staining were performed. The main outcomes were subepithelial lymphocyte density (LyD), follicular density (FD), and follicular area (FA). The secondary outcomes were follicular reflectivity (FR), and lymphocyte density (FLyD), and CD3 and CD20 positivity.
RESULTS:
Conjunctiva-associated lymphoid tissue was observed in all subjects (97% only superior and 3% in both superior and inferior tarsum). Lymphocyte density ranged from 7.8 to 165.8 cells/mm(2) (46.42 [18.37]; mean [SD]), FD from 0.5 to 19.4 follicles/mm(2) (5.3 [3.6]), and FA from 1110 to 96,280 mm(2) (26,440 [26,280]). All three parameters showed a highly significant inverse cubic relationship with age (P < 0.001); that is, in the first and last parameters a steep decline up to 35 years and above 65 years of age, with a plateau phase between these ages, whereas FA had a gradually decreasing rate of loss over the studied age range. CD3 and CD20 IC were consistent with these results.
CONCLUSIONS:
In vivo confocal microscopy was effective in revealing CALT and modifications these structures undergo with aging. Aging correlated with an involution of all parameters defining lymphoid structures. These modifications may account for the decrease of mucosal immune response and increase of ocular surface diseases in the elderl
Structural modifications and tissue response after standard epi-off and iontophoretic corneal crosslinking with different irradiation procedures
No full textPURPOSE: The aim of this study is to investigate modifications in human cadaver corneas after different crosslinking procedures, including standard epi-off treatment, iontophoresis imbibition, and different exposure to ultraviolet A (UVA) sources (30 minutes at 3 mW and 9 minutes at 10 mW).
METHODS:
A total of 12 human cadaver corneas was examined and divided as follows: 3 served as control (group 1), 3 were treated with a standard epi-off procedure (group 2), 6 underwent iontophoresis imbibition for 5 minutes, and then 3 were irradiated for 30 minutes with 3 mW UVA (group 3), and 3 for 9 minutes at 10 mW UVA (group 4). Deformation amplitude index was measured before and after the corneas underwent treatment. After treatment, corneas were prepared for hematoxylin-eosin and immunohistochemistry evaluation. The expression of TUNEL, matrix metalloproteinase-1 (MMP-1), collagen type I, and CD34 was investigate in all samples.
RESULTS:
The deformation amplitude index decreased in all groups, in particular in group 4, indicating an improvement of corneal biomechanical properties. Immunohistochemical staining showed a significant stromal alteration in group 2, mild damage in group 3, and no modifications in corneal morphology in group 4. The TUNEL (P < 0.001) and MMP-1 (P = 0.002) positivity was more evident in group 4. Collagen type I positivity significantly increased in groups 3 (P = 0.002) and 4 (P = 0.002). The CD34 expression was more evident in groups 2 (P = 0.003) and 3 (P = 0.003).
CONCLUSIONS:
Iontophoresis imbibition followed by UVA irradiation for 9 minutes at 10 mW determined less tissue damage and better stromal remodeling
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